An ESDIAD Study of Chemisorbed Hydrogen on Clean and H-Exposed Si(111)- (7x7)
Abstract
The chemisorption of H on Silicon(111)-(7x7) has been studied by digital ESDIAD and temperature programmed desorption methods. It has been found that residual Hydrogen in the bulk of the Si(111) can be transported to the surface upon annealing to temperatures above approx. 1000 K. The adsorption of atomic H on Si(111)-(7x7) results in a mixture of monohydride and polyhydride species as detected by H(+)ESDIAD. Thermal desorption from the H-saturated surface liberates (Beta 3(-), Beta 2(-) + B1 - H2) species as well as SiH4(g). Heating the H-saturated surface to 1040 K results in a significant disordering of the surface, leading to Si sites which produce highly tilted Si-h bond directions. The occupation of these sites with H produces surface species exhibiting high polar angles from the surface normal for H(+) desorption by an ESD process with a high ionic cross section compared to the cross section observed for normal mono- and polyhydride surface species. (JG)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 11, 1990
- Accession Number
- ADA222327
Entities
People
- J. T. Yates Jr.
- P. A. Taylor
- R. W. Wallace
- Wolfgang J. Wolfgang J. Choyke
Organizations
- University of Pittsburgh